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  2. Pulse-width modulation - Wikipedia

    en.wikipedia.org/wiki/Pulse-width_modulation

    (In fact, PWM is equivalent to the sum of two sawtooth waves with one of them inverted.) [10] Class-D amplifiers produce a PWM equivalent of a lower frequency input signal that can be sent to a loudspeaker via a suitable filter network to block the carrier and recover the original lower frequency signal. Since they switch power directly from ...

  3. Power electronics - Wikipedia

    en.wikipedia.org/wiki/Power_electronics

    The carrier-based PWM technique compares the AC output waveform, v c, to a carrier voltage signal, v Δ. When v c is greater than v Δ , S+ is on, and when v c is less than v Δ , S− is on. When the AC output is at frequency fc with its amplitude at v c , and the triangular carrier signal is at frequency f Δ with its amplitude at v Δ , the ...

  4. Carrier wave - Wikipedia

    en.wikipedia.org/wiki/Carrier_wave

    In telecommunications, a carrier wave, carrier signal, or just carrier, is a periodic waveform (usually sinusoidal) that conveys information through a process called modulation. One or more of the wave's properties, such as amplitude or frequency, are modified by an information bearing signal, called the message signal or modulation signal .

  5. Servo control - Wikipedia

    en.wikipedia.org/wiki/Servo_control

    Servo and receiver connections A diagram showing typical PWM timing for a servomotor. Servo control is a method of controlling many types of RC/hobbyist servos by sending the servo a PWM (pulse-width modulation) signal, a series of repeating pulses of variable width where either the width of the pulse (most common modern hobby servos) or the duty cycle of a pulse train (less common today ...

  6. Pulse-frequency modulation - Wikipedia

    en.wikipedia.org/wiki/Pulse-frequency_modulation

    It is analogous to pulse-width modulation (PWM), in which the magnitude of an analog signal is encoded in the duty cycle of a square wave. Unlike PWM, in which the width of square pulses is varied at a constant frequency , PFM fixes the width of square pulses while varying the frequency .

  7. Random pulse-width modulation - Wikipedia

    en.wikipedia.org/wiki/Random_pulse-width_modulation

    For conventional PWM, the PSD can be directly determined from the Fourier Series expansion of the PWM signal. However, the PSD of the RPWM signals can be described only by a probabilistic level using the theory of stochastic processes such as wide-sense stationary (WSS) random processes. [4] Comparison of the PSD of PWM vs RPWM signals

  8. Pulse-repetition frequency - Wikipedia

    en.wikipedia.org/wiki/Pulse-repetition_frequency

    The pulse-repetition frequency (PRF) is the number of pulses of a repeating signal in a specific time unit. The term is used within a number of technical disciplines, notably radar. In radar, a radio signal of a particular carrier frequency is turned on and off; the term "frequency" refers to the carrier, while the PRF refers to the number of ...

  9. Spread spectrum - Wikipedia

    en.wikipedia.org/wiki/Spread_spectrum

    The core principle of spread spectrum is the use of noise-like carrier waves, and, as the name implies, bandwidths much wider than that required for simple point-to-point communication at the same data rate. Resistance to jamming (interference). Direct sequence (DS) is good at resisting continuous-time narrowband jamming, while frequency ...